In patients suffering from multiple trauma the initially responding emergency physician on the scene will take a blood sample for thrombelastometry immediately after i.v. access is established. According to the initial trauma life support protocols a number of patients will receive a dose of tranexamic acid during the initial treatment on the scene or during transport to the hospital. A second blood sample will be taken after arrival in the resuscitation area of the hospital. Thrombelastometric measurements will be performed with both blood samples and the extent of hyperfibrinolysis in both samples will be compared. In a second step the outcome of the patients who received tranexamic acid on the scene will be compared to those who did not receive the drug before reaching hospital.